how can i get the onchange function work on hidden text field.

HI,

How to get the value of date  onchange of Hidden text field value
i want to get the value in the text box whenever there is change date  .
 the value is created when the calendr pop up and close. how can i get the onchange function work on hidden text field.


<!-- hidden fields -->
<input type="hidden" id='nStart' name='nStart'>

<input type="hidden" id='nEnd'  name='nEnd'>

<input type="hidden" id='nWork' name='nWork'>

plz find the attached files
expert.php
cal.jpg
cal2.js